1933 fan belt

[Ed Saniewski]

The 40-8620 fan belt I have is just a little bit too small for my engine. Does anyone know what the next size up belt would be? Tried to go to local Advance auto parts store , but they are unable to help or measure my belt and find the next size up. Thanks

 

[51504bat]

If an autoparts store can't measure a fan belt you need to find another one.


Mr. Google lists a 40-8620 fan belt as being 55". Gates makes a 56" one.
Gates Super HC V-Belt 5/8 Inch x 56 Inch - 5V560

O'Reily's lists it but you have to have it delivered. Whatever you do buy make sure it's an automotive belt not one for a lawn mower or similar application.

 

[ford38v8]

Ford specs and actual lengths of available V belts have differed in certain applications. A too-short belt can sometimes be installed by first loosening the generator mount sufficiently to tilt the generator downward to accept the belt, then re-installing the generator to it's correct position.
In all belt tightening operations, a small block of wood under the generator as a fulcrum with a long screwdriver used as a lever prevents many under-hood cuss words.

 

[19Fordy]

I use for38v8's technique and it works fine by tilting the generator.

 

[Ed Saniewski]

I think I discovered the problem, the generator on my car appears to be a 1934 generator with a 4 5/16 inch pulley with the cooling vanes instead of a 4 inch pulley. So the search begins for the correct pulley.

 

[leon bee]

I try to look up all that stuff before going to the parts store. Using your number, should be able to find next size. My NAPA guys still measure belts.

 

[ford38v8]

There used to be V belt measuring devices hanging on walls in gas stations. Now those that survive are in the display cases of car collectors.

 

[Don Rogers]

Here's an old belt sizing chart that I used.

 

[Model51]

Don't forget that whatever belt you end up using, it shouldn't be too tight when it's finally in place. It should fit with some play (about 1" side to side play) otherwise you may put too much stress on the water pump and generator bearings. Also, the 4" diameter pulley will spin your generator faster and increase the charging rate.

 

[petehoovie]

Here's an old belt sizing chart that I used.

 

[Flathead Fever]

The parts store should have been able to measure that belt and give you a larger one, they usually come in 1/2" lengths. They have a belt gauge for measuring used belts just for that reason. I worked as a fleet mechanic, and we stocked at least 100 different belts for our vehicles but every once in a while, we had something custom we had to figure out. At home I don't have 100 different belts to choose from. What I do is I keep my old warn out belts and I cut them. Then I set the generator or alternator on its smallest setting and wrap the belt around the pulleys and take a reading of the length I need. make sure you are using the correct width belt. Then I add just a little bit to the measurement and that usually works out fine. Don't throw your old belts away, they are handy tools.